SPOILER WARNING: The following article contains major spoilers for Deadpool 2. If you have not yet seen the film, please bookmark this page, and save the read until after your screening!

The surprise appearance of the Juggernaut in Deadpool 2 is certainly one of the movie's most excellent surprises -- but in that department the film also leaves audiences with a bit of a mystery.

After all, the end credits don't actually say who plays the character, instead just saying that he stars as "Himself." Fortunately for you, I wasn't comfortable with this lingering question, so I went hunting for the answer.

When I spoke with director David Leitch on the subject earlier this week, he revealed that he himself played the Juggernaut along with Ryan Reynolds in performance capture -- with Reynolds also performing the dialogue. The filmmaker told me,

"The spoiler is Juggernaut is sort of a combination of Ryan and myself. And it only became, and this is a spoiler spoiler. It only came out of just the necessity of change, and you're getting into the post-process, and we're like, 'Okay, now we need a face animator actor.' And I'm in the editing room, and Ryan's writing alts, and we're like, 'I'll just go do it.' And then the animators are going to change it anyway."

Ryan Reynolds played and voiced some of Juggernaut. Carlos Alvarez/Getty Images

I learned a lot about the Juggernaut when I sat down for a one-on-one interview with David Leitch during the Deadpool 2 press day in New York, starting with the fact that he and Ryan Reynolds switched off doing the performance capture work during production. Apparently it was really a matter of convenience, as they felt that they didn't need outside help bringing the character back to the big screen for the first time since X-Men: The Last Stand.

This was Juggernaut in "X-Men: The Last Stand." Marvel/Fox

Clearly the convenience factor worked out extremely well on set, with David Leitch and Ryan Reynolds always being around during the making of Deadpool 2, but it also extended to recording sessions of the voice during post-production. According to Leitch, his star occasionally came in to record some additional dialogue for Deadpool anyway, do during those sessions he was able to get all of Juggernauts lines as well. Said Leitch,

"Ryan did some performance capture for certain dialogue bits. And then he provided the voice, which we altered, which allowed us to, when we we're in post, we're doing some alts for Deadpool. It'd be like, 'Okay, let's just switch into Juggernaut mode, try this.' As opposed to 'Let's bring in somebody, wait for them, call time,' all this. It was a tight unit. Ryan's got another franchise!"

Much like Deadpool and Colossus, Juggernaut is yet another fan-favorite Marvel character that this branch of the X-Men franchise has managed to buy back to a certain degree. Vinnie Jones' version of the character from X-Men: The Last Stand is far more infamous than it is popular, mostly because of one terribly embarrassing meme-inspired moment. Fortunately, Deadpool 2 creates a new version of the famed villain who is much more like his comic book counterpart than the previous interpretation.

Not only is Juggernaut, a.k.a. Cain Marko, physically more accurate (much bigger than just a normal human), the movie even manages to dig a bit into his important backstory. Specifically, while we don't get the full explanation of his backstory -- which is fairly complicated --we do at least learn that he is Professor Xavier's brother. While talking with screenwriters Rhett Reese and Paul Wernick, they told me that getting into more of the character's history wasn't something that was really on the table, but that they definitely wanted to give fans a treat. Said Reese,

"We did think that Juggernaut had not been treated as well as he could have been in previous movies, and we wanted to rectify that... we worried a little bit about too much backstory, like with Cable in particular. We were like, 'Let's make him a man of mystery. The whole Nathan Summers clone, techno-virus, all that stuff, we just thought we were going to overload our audience. But we did sneak in the bit about Professor Xavier."

At the end of Deadpool 2, Juggernaut suffers a fairly embarrassing defeat, as he gets a live wire shoved up his butt before being dumped in a pool -- but you shouldn't be too concerned about him. Not only did David Leitch suggest in my interview that Juggernaut survived the battle, but he also explained that he is excited to potentially play around with the character a lot more in future films. Said Leitch,

"I think there's ground in the future to really expand on his powers. He only comes into the movie in the third act, and we kind of set the location, and I mean there's only so much you can do with him in a mano a mano fight, you know? The Juggernaut's action comes from him like plowing through stuff, and he's unstoppable, and we just didn't really have that in the construct of the set piece. So I do look forward to in future installments, if they want to bring him back, to watch him wreck some shit."

We'll have to wait and see if Juggernaut gets his chance to truly wreck some shit in a future film -- but for now we can definitely be happy with the version that Deadpool 2 delivers.